Think of the jumble of points you want to write about as though they were a pile of dirty laundry. You need to break the laundry down into separate piles so that, for instance, whites and coloureds are washed separately. In the same way, you need to sort the points into sections and paragraphs. The labels for each pile are analogous to the headings and sub-headings under which you will write about each point.
So your document begins with two headings:
1. Whites
2. Coloureds
Where, then, do you put grey items? The discussion should bring out the fact that this will depend on your purpose in sorting the items. Coloured pieces are kept separate to avoid staining white linen, so the greys will go into whichever pile you intend to wash them with.
Let's assume that greys are to be washed with whites, and put them in that pile. You now have a pile labelled whites containing whites and greys. How best to correct this so that the heading reflects the contents accurately and comprehensively? Is there is a generic term for whites and greys? Or would it be better to head this sub-section others?
Next you find a red woolen jersey. Where does that go? As it would shrink if washed with the linen it will need a new pile, so our document might now have a table of contents something like this:
1. Coloureds
(A) Linen2. Others
(B) Wool
Then comes a suit. But that has to go the dry-cleaners rather than the launderette, so the document must be re-organized:
1. Washing
(A) Coloureds2. Dry cleaning
(a) Linen(B) Others
(b) Wool
Once everything has been cleaned you will have to re-sort it to put away, and the different purpose will dictate different headings:
1. Wardrobe
(A) Phil's side2. Chest of drawers
(B) Liz's side
(A) Phil's drawer
(B) Liz's drawer
The laundry analogy on which I based this exercise was suggested to me by Professor J. Kimble of the Thomas M. Cooley Law School.